Disable conv cache emptying (#101038)
We warmup cudagraph trees in the cudagraph memory pool so that if we are part of the way through your run, and a large majority of memory is already allocated to cudagraphs, we dont try to allocate again to eager which would split memory pool in half. However this means this is causing us to fail the following assert due to the `emptyCache` call in CUDNN benchmarking: https://github.com/pytorch/pytorch/blob/main/c10/cuda/CUDACachingAllocator.cpp#L2959.
Disable the empty cache call during cudagraph warmup to fix error. Disabling did not have a significant affect on memory:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/101038
Approved by: https://github.com/shunting314, https://github.com/ngimel
